1. Field of the Invention
The present invention relates to a method and apparatus for providing presentation managing information which is required for a digital television to present received a program variously and immediately when reproducing a digital data stream recorded on a disk recording medium such as a high density digital versatile disk (referred as ‘HDVD’ hereinafter).
2. Description of the Related Art
FIG. 1 is block diagrams of a DVD player and a digital television which are connected each other through a digital interface such as IEEE 1394 standard.
The DVD player 100 comprises an optical pickup 2 for detecting data recorded on a DVD 1; a demodulator 3 for demodulating and error-correcting the detected data; a scrambler 4 (or a copy protecting device) for scrambling data outputted from the demodulator 3 with copy protecting codes; a path selector 5 for selecting one or two output paths for data scrambled with the copy protecting codes; a data parser 6 for parsing the data stream whose type is program stream (PS) and received through the path selector 5, into presentation and navigation data and then parsing the presentation data into audio, video and sub-picture data again; decoders 7 and 8 for decoding the parsed audio and video data into uncompressed data respectively; a presentation engine 9 for combining the decoded audio and video data into a digital audio signal and a digital video signal; D/A converters 10 and 11 for converting the digital audio and video data into corresponding analog signals respectively; a microcomputer 12 for controlling the reproduction operation for the optical disk 1 depending upon the navigation data from the data parser 6 and a key command from a user; a memory 15 storing data necessary for the control operation of the microcomputer 12; a PS/TS converter 13 for converting the PS outputted from the path selector 5 into a transport stream (TS); and an interface 14 for transmitting the converted TS through a IEEE 1394 digital communication line.
The digital TV 200 comprises an interface 21 for receiving the TS from the DVD player 100 through the IEEE 1394 digital communication line; a deMUX 23 for demuxing the received TS into audio and video data; decoders 24 and 25 for decoding the audio and video data into uncompressed audio and video data respectively; D/A converters 26 and 27 for converting the uncompressed digital data into corresponding analog audio and video signals respectively; a microcomputer 22 for generating control signals for each element corresponding to a user's key input; an on-screen displaying (OSD) circuitry 28 for outputting character signals corresponding to an advisory message provided by the microcomputer 22 onto a screen; a mixer 30 for mixing the character signals with the video signals; and a memory 29 storing data necessary for the control operation of the microcomputer 22.
A key entering means 50 such as a remote controller for controlling the operations of the DVD player 100 and/or the D-TV 200 is also shown in FIG. 1.
In the DVD player 100 configured as FIG. 1, recorded signals detected from the DVD 1 by the optical pickup 2 are demodulated into PS by the demodulator 3. The PS is separated into audio, video and sub-picture data of MPEG format by the data parser 6, and the MPEG-formatted data are converted into audio and video signals by the decoders 7, 8, and 9, the presentation engine 10, and the D/A converters 11 and 12. Also, the PS is sent to the PS/TS converter 13 through the path selector 5. The PS/TS converter 13 decodes the PS and interprets the stream identification number, sorts out the PS into program specific information (PSI) for controlling program presentation, presentation data containing audio and video data, and system clock data.
The PSI and system clock data are used as information for controlling presentation of program and system clock synchronization, respectively.
The presentation data are converted into TS whose format is acceptable to the digital TV 200 and transferred to the digital TV 200 through the IEEE 1394 interfaces 14 and 21. Accordingly, the digital TV 200 can present high-quality digital video and audio to a viewer after decoding the received TS.
A difference between aforementioned PS and TS is as follows.
The PS is composed of several packs and each pack has packetized elementary stream (PES) packets containing digitized video, audio, and additional information data. A PES packet can contain data whose size is variable so that the size of a PES packet may not be same all the time.
On the contrary, the TS is composed of transport packets (TPs) and each packet has a fixed length of 188 bytes including its packet header.
Accordingly, when converting a PS into a TS, each PES packet of PS should be divided into packets of TS sequentially and necessary header information is added to each divided transport packet (TP) at that time. Because a PES packet is divided into multiple TPs, the remaining area of the last TP is stuffed with null data after writing all data of a PES packet in the multiple TPs.
However, a recently-developed HDVD player has adopted the TS format as the recording-type of data stream for a HDVD so that a data stream reproduced from a HDVD can be directly signal-processed in a digital television in consideration that a HDVD player is connected with a digital television. Therefore no TS/PS conversion will be required in transmitting the reproduced digital data stream to the digital television. However, the digital television receiving the transport stream needs presentation managing information such as program specific information (PSI) for various and stable video and audio presentation. It is standard that the PSI is periodically or intermittently inserted in the digital broadcast signal.
Accordingly, the method for recording presentation managing information such as the PSI repeatedly on a HDVD may be considered. However, if the presentation managing information is repeatedly recorded on a HDVD, the space for program data on the disc is remarkably decreased.